1. Field of the Invention
The present invention relates to liquid crystal displays, and more particularly, to reflection type color liquid crystal displays (LCDs) having an improved reflection film and an improved color filter layer.
2. Description of the Related Art
Generally, reflection type LCDs use a twisted pneumatic liquid crystal or a super-twisted pneumatic liquid crystal to display a monotone picture. However, with demand for color pictures, research into reflection type color LCDs including a color filter layer is being actively conducted.
Such reflection type LCDs having a color filter layer include an LCD adopting a guest host technique, in which a black dye is mixed in a liquid crystal, and a polymer scattering technique, in which a liquid crystal is scattered on a high molecular polymer. These techniques provide a good luminance because they do not use a polarization plate, but provide a low contrast.
To solve this problem, Korean Patent Publication No. 2001-022609 discloses a reflection type LCD which reflects external light using a reflective polarization plate, or transmits light radiating from a backlight. Such a display device improves a contrast by using a reflection type polarization plate, but degrades a luminance of the display device.
To solve this problem, there is provided a conventional reflection type LCD having an LCD portion, a color filter layer, and a reflection film. The LCD portion forms a picture using a liquid crystal. The color filter layer includes a patterned red filter layer, a patterned green filter layer, and a patterned blue filter layer so as to color the picture formed by the LCD portion. The reflection film is formed below the color filter layer.
FIG. 1 shows such a reflection type LCD in which a reflection film 11 and a color filter layer 12 are deposited on a substrate 10. As shown in FIG. 1, the reflection film 11 is formed on the substrate 10 and a color filter layer 12 having patterned red, green, and blue filter layers 12R, 12G, and 12B is formed on the reflection film 11. Apertures 11a which transmit light radiating from a backlight (not shown) are formed in parts of the reflection film 11 that face the red, green, and blue filter layers 12R, 12G, and 12B.
However, in this structure, the thickness of the color filter layer 12 formed on the reflection film 11 is uniform over a transmissive area corresponding to the apertures 11a of the reflection film 11, and a reflective area of the reflection film 11. Thus, the color filter layer 12 provides a poor color reproducibility of color pictures.